JPS6118038B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a condensate recovery device used for recovering condensate generated in a steam system to a boiler.

Condensate generated within the steam system is generally exhausted from a steam trap. In order to collect this condensate and pump it to a desired location such as a boiler, the outlet side of the steam trap is connected to a condensate pump device. In this case, the pressure on the outlet side of the steam trap increases, the pressure difference between the inlet side and the outlet side of the steam trap becomes small, and the amount of condensate discharged decreases. A problem arose in that condensate stagnation degraded the thermal efficiency of steam-using equipment, etc., so a condensate recovery device as shown in Figures 5 and 6 was used.

In FIG. 5, 1 is a steam supply passage, 2 is a valve that controls the passage of steam through the passage, 3 is steam-using equipment, and 4 is a steam trap attached to the condensate discharge side of the equipment. 5 is a condensate pump means, 6 is a condensate inlet passage that guides the condensate discharged from the steam trap 4 to the condensate pump means 5, and 7 is a condensate inlet passage 6.
8 is a pressure regulating valve, and 9 is a condensate outflow passage that leads condensate from the condensate pump means 5 to a desired location such as a boiler. The pressure regulating valve 8 shown in FIG. 6 was used.
In FIG. 6, 10 is a valve casing, 11 is an inlet, 12 is a valve port, 13 is an outlet, 14 is a valve body, 15
1 shows a piston connected to the valve body 14, 16 a pressure guiding passage, 17 an elastic body, and 18 an adjustment rod.

In the above condensate recovery device, the pressure on the condensate inlet passage 6 side acts on the lower surface of the piston 15 of the pressure regulating valve 8 through the pressure guiding passage 16, and the elastic force of the elastic body 17 acts on the upper surface of the piston 15. However, when the pressure on the condensate inflow passage means 6 side becomes higher than the set pressure, the valve opens, and the fluid on the condensate inflow passage 6 side is discharged through the pressure relief passage 7, and the pressure on the condensate inflow passage 6 side is reduced. Keep the pressure below the set pressure. The pressure difference between the inlet side and the outlet side of the steam trap 4 is maintained appropriately to prevent a decrease in the amount of condensate discharged from the steam trap 4 and a deterioration in the thermal efficiency of steam-using equipment due to accumulation of condensate. do. However, there are pressure fluctuations in the steam system, and the pressure on the inlet side of the steam trap 4 also fluctuates. Therefore, the pressure on the outlet side of the steam trap 4 must always be low with respect to pressure fluctuations on the inlet side, and the set pressure of the pressure control valve 8 must be set to keep the minimum value of the fluctuations in the pressure on the inlet side of the steam trap 4. Considering this, it was set extremely low. In this case, a large amount of fluid on the condensate inflow passage 6 side is discharged through the pressure relief passage 7, and the amount of condensate recovered to a desired location such as a boiler is reduced.
The loss of condensate recovery was increasing.

In view of the above circumstances, it is an object of the present invention to provide a condensate recovery device with a small recovery loss of condensate. The present invention achieves the above object by providing a pressure relief passage branching from the condensate inlet passage means that communicates the condensate discharge means such as a steam trap and the condensate pump means, and setting the pressure difference before and after the condensate discharge means. This is achieved by disposing a differential pressure regulating valve in the pressure relief passage for discharging the fluid in the condensate inflow passage through the pressure relief passage so as to maintain the same value.

Next, the present invention will be explained based on the embodiments shown in FIGS. 1 and 2. In FIG. 1, corresponding parts common to those in FIG. The pressure relief passage 7 is equipped with a differential pressure regulating valve 2 shown in FIG.
Place 1.

The specific structure of the differential pressure regulating valve 22 shown in FIG. 2 will be explained. A valve seat member 26 is attached to a main body 25 that forms an inlet 23 and an outlet 24 connected to the condensate inflow passage 6 side of the pressure relief passage 7. The valve seat member 26 has a cylindrical shape and has a valve port 27 formed at its inner end. Its inner peripheral surface has a slightly larger diameter than the valve port 27 and is finished smoothly. The valve port 27 and the inner peripheral surface are continuous at the annular valve seat. A passage 28 is formed in the lower peripheral wall of the valve seat member 26.
Inlet 23 communicates with outlet 24 through valve port 27 and vent 28 . The tip of the valve seat member 26 and the main body 25
An O-ring gasket is interposed between the opposing walls of the valve seat member 26 and between the upper peripheral wall of the valve seat member 26 and the opposing wall of the main body 25.

A cylindrical valve body 29 is slidably fitted onto the inner peripheral surface of the valve seat member 26 via an O-ring packing. The valve surface at the inner end can close the valve port 27 by coming into contact with a valve seat surface that defines the valve port 27. Valve rods 30 having the same diameter and extending coaxially are integrally formed at both ends of the valve body 29.

An intermediate member 33 is attached to the end surface of the main body 25 through which the insertion hole of the valve seat member 26 is opened, with a bolt and nut via a gasket. The valve stem 30 extends outwardly through a central hole 41 in the septum of the intermediate member 33.
A piston 34 is attached to the free end of the valve stem 30 protruding from the intermediate member with a nut via an O-ring gasket.

The piston 34 is slidably fitted into a cylinder member 35 disposed around the piston via an O-ring packing. Cylinder member 3 between intermediate member 33
The lid 36 is attached to the intermediate member 33 with bolts and nuts while holding the lid 36. A gasket is interposed between the cylinder member 35, the intermediate member 33, and the lid 36. An adjustment rod 37 is screwed onto the outer end of the lid 36 through an O-ring packing. Adjustment rod 3
A coil spring 39 is disposed between the piston 34 and a spring receiving member 38 disposed in contact with the inner end of the piston 7 via a sphere.
intervene.

The space 40 facing the lower surface of the piston 34 constitutes a first pressure chamber, and the condensate inlet passage 6 side pressure, that is, the steam trap 4 The outlet side pressure of Further, a coil spring 51 is disposed within the space 40 to bias the piston 34 in the valve opening direction. The space 42 facing the upper surface of the piston 34 is the second
A pressure introduction port 43 provided in the lid 36 is opened to form a pressure chamber, and the pressure on the inlet side of the steam trap 4 acts through the pressure capillary tube 22.

The spring 39 opposes the elastic force of the spring 51 and adjusts the elastic force that urges the piston 34 in the valve opening direction, and may be omitted when a constant elastic force is applied to the piston 54. The pressure on the inlet side of the steam trap 4 acts on the piston 34 of the valve 21 from the upper surface, and the pressure on the outlet side of the steam trap 4 and the difference between the elastic forces of the springs 51 and 39 acts on the piston 34 from the lower surface. 34 is displaced to a position where the above forces are balanced. The valve body 29 changes the opening degree of the valve port 27 in conjunction with the piston 34, releases the pressure of the fluid on the condensate inflow passage 6 side through the pressure relief passage 7, and releases the fluid from the condensate inflow passage 6.
Control side pressure.

As a result, with respect to fluctuations in the pressure on the inlet side of the steam trap 4, the pressure on the outlet side of the steam trap 4, that is, the pressure on the condensate inflow passage 6 side, is
The pressure is controlled to be lowered by the pressure corresponding to the difference in elastic force of 9. Also, this pressure difference is determined by the adjustment rod 37.
It can be changed by screwing the springs 51 and 39 back and forth and adjusting the force of the difference in elastic force between the springs 51 and 39.

Therefore, in the above embodiment, the pressure on the outlet side of the steam trap 4, that is, the pressure on the side of the condensate inlet passage 6, is controlled to be lower by a set value than the pressure on the inlet side of the steam trap 4.
The steam trap 4 operates stably because the pressure difference between the inlet side and the outlet side is constant. Therefore, the problem of reducing the amount of condensate discharged from the steam trap 4 and causing condensate to stay on the inlet side of the steam trap 4 does not occur. Further, the valve 21 is connected to the steam trap 4.
In response to fluctuations in the inlet pressure of the steam trap 4, the outlet pressure can be changed by keeping it lower than the set value, and there is no need to consider the minimum fluctuation value of the inlet pressure of the steam trap 4. By reducing the amount of fluid discharged through the passage 7, it is possible to reduce condensate recovery loss.

Next, explanation will be given based on the embodiment shown in FIG. However, the same reference numerals are given to the same parts as in the above embodiment, and the explanation thereof will be omitted. The differential pressure regulating valve means 61 may be electrical or pneumatic. The pressure on the inlet side and the outlet side of the steam trap 4 is taken out through thin tubes 62 and 63, and a differential pressure transmitter 6
Lead to 4. The regulator 65 compares the value received from the differential pressure transmitter 64 with the set value, and sends a valve operation signal to the valve position 66 as necessary. Valve position 66 opens and closes control valve 67. 68 indicates supply pressure or power. Furthermore, depending on the control method, a pneumatic converter may be used. 69 indicates a signal transmission line.

The regulator 65 controls the opening and closing of the control valve 67 so that the pressure difference between the inlet side and the outlet side of the steam trap 4 becomes a set value. For example, if the pressure difference is not smaller than the set value, the control valve 67 is opened wide and the fluid on the condensate inflow passage 6 side is discharged through the pressure relief passage 7,
If the pressure on the condensate inflow passage 6 side is lowered and the pressure difference becomes large, the control valve 67 is operated to increase the pressure on the condensate inflow passage 6 side.

In the above embodiment, electrical or pneumatic means is used for the differential pressure regulating valve means 21, and PI and PDI are used as necessary.
Control can be performed easily. Moreover, stable and reliable control can be performed against pressure fluctuations in the condensate inlet passage 6.

Next, a description will be given based on the embodiment shown in FIG. However, the same reference numerals are given to the same parts as in the above embodiment, and the explanation thereof will be omitted. Steam-using equipment 3'・
3'' are used with different high and low pressures. Steam traps 4' and 4'' are also used with different working pressures. The condensate inlet passage 6' is connected to the steam trap 4'.
4" to guide both condensate. Pressure relief passage 7
The differential pressure regulating valve 21 shown in FIG. A closed circulation passage 73 that connects the suction port with a closed circulation passage 73, an ejector member 74 arranged in the middle of the circulation passage 73, a valve 75 that adjusts the injection flow rate of the ejector member 74, and a control valve 76 arranged in the condensate outflow passage 9'.
Use something consisting of. The condensate inflow passage 6' opens into the suction chamber of the ejector member 74, and the condensate outflow passage 9' opens in the middle of the circulation passage 73. In addition, the control valve 76 is set to a differential pressure transmitter 79 that takes out the pressure on the suction port side of the pump 72 and the pressure on the condensate inlet passage 6' side through the thin tubes 77 and 78, and the received value from the differential pressure transmitter 79. a regulator 81 that compares the values and sends a control signal to the valve positioner 80 as necessary;
and a valve positioner 80 that opens and closes the control valve 76. 90 indicates supply pressure or power. Here, the setting value of the regulator 81 is such that the suction port side pressure of the pump 72 is adjusted to an appropriate pressure that takes into consideration the margin between the required pushing pressure of the pump 72 and the boosting limit pressure of the ejector member 74 in the condensate passage 6'.
Based on the time when the side pressure becomes higher than that, the control valve 76 opens and pumps condensate through the condensate outflow passage 9', and when it becomes smaller, the control valve 76 closes and pumps the condensate. stop. Even if the pressure on the condensate inlet passage 6' side fluctuates, the pressure difference between the condensate inlet passage 6' and the suction port side of the pump 72 is kept constant.
This pressure difference acts as a pushing pressure for the pump 72 and prevents the pump 72 from idling.

Therefore, in the above embodiment, the differential pressure regulating valve 21 ensures the pressure difference necessary for the draining action of the steam trap 4, and also prevents pressure fluctuations on the condensate inlet passage 6' side that occur for this purpose. By using the condensate pump means 71 that does not cause failure of condensate pumping, it is possible to obtain a condensate recovery device that can stably pump condensate. Further, the differential pressure control valve 21 is designed to control the pressure on the condensate inlet passage 6' side in accordance with fluctuations in the pressure on the inlet side of the low pressure steam trap 4''. ′ pressure difference can be maintained at the same time.

In this way, the present invention maintains a predetermined pressure difference between the inlet side and the outlet side of the condensate discharge means such as a steam trap, even if the pressure of the steam system fluctuates. Make sure to drain the water. At the same time, the pressure in the condensate inlet passage is adjusted in accordance with pressure fluctuations in the steam system, and the amount of condensate discharged through the pressure relief passage is minimized, so a condensate recovery device with less loss in condensate recovery can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a condensate recovery device according to an embodiment of the present invention, FIG. 2 is a sectional view of a differential pressure regulating valve, and FIGS. 3 and 4 are schematic diagrams of a condensate recovery device according to other embodiments. FIG. 5 is a schematic diagram of a conventional condensate recovery device, and FIG. 6 is a schematic sectional view of a conventional pressure regulating valve. 1: Steam supply passage, 3, 3', 3'': Steam using equipment, 4, 4', 4'': Steam trap, 5: Condensate pump means, 6, 6': Condensate inflow passage, 7: Discharge Pressure passage, 9/9': Condensate outflow passage, 21: Differential pressure control valve, 23: Inlet, 24: Outlet, 27: Valve port, 2
9: Valve body, 34: Piston, 40: Space, 51:
Coil spring, 61: Differential pressure regulating valve means.

Claims (1)

[Claims] 1. A condensate pump means, a condensate discharge means such as a steam trap, a condensate inlet passage means for guiding condensate discharged from the condensate discharge means to the condensate pump means, and a condensate inlet passage. The branched pressure relief passage means detects the inlet side pressure and the outlet side pressure of the condensate discharge means, and the fluid in the condensate inflow passage means is discharged through the pressure relief passage means so that the difference between both pressures becomes a set value. A condensate recovery device comprising differential pressure regulating means and condensate outflow passage means for causing condensate to flow out from the condensate pump means to a desired location. 2. A movable pressure-responsive wall member formed with a pressure-receiving surface of approximately the same area on which the inlet side pressure and the outlet side pressure of the return discharge means act from opposite directions; the opening degree is adjusted in conjunction with the pressure-responsive wall member. The valve member is an elastic body disposed so as to bias the pressure-responsive wall member from the same direction as the outlet side pressure and create a pressure difference corresponding to the biasing force between the inlet side and the outlet side of the condensate discharge means. A condensate recovery device according to claim 1, using a differential pressure regulating valve means. 3 A differential pressure transmitter that detects the inlet and outlet pressures of the valve and condensate discharge means and transmits the pressure difference, and compares the received value from the differential pressure transmitter with the set value and determines whether there is a pressure difference in the set value. Claim 1 uses a differential pressure regulating valve means comprising a regulator that transmits an operating value so that the pressure is maintained, and an operating section such as an electric type that operates the valve according to the received value from the regulator. Condensate recovery device as described. 4. Claims 1, 2, or 3 using a condensate pump means consisting of a pump, a closed circulation passage connecting the discharge port and the absorption port of the pump, and an ejector member disposed in the circulation passage. Condensate recovery device as described. 5 A valve arranged in the condensate outflow passage means, a differential pressure transmitter that detects and transmits the pressure difference between the condensate inflow passage means and the pump suction side, and a value received from the differential pressure transmitter and a set value are compared. The pump responds to pressure fluctuations in the condensate inlet passage means, consisting of a regulator that transmits an operating value so that the pressure difference is maintained at the set value, and an operating section that operates the valve according to the value received from the regulator. The condensate recovery device according to claim 4, which uses a condensate pump means having a stable operation means.